1. Field of the Invention
Embodiments of the present disclosure relate to the field of designing liquid crystal displays (LCDs), and more particularly to a method for designing a polymer-dispersed liquid crystal (PDLC) transflective LCD.
2. Description of Related Art
Transmissive liquid crystal displays (LCDs) have been widely used in electronic devices, such as computers, high-definition televisions (HDTVs), mobile devices and so on. The most commonly used transmissive 90 degree twisted-nematic (TN) LCDs exhibit a high contrast ratio due to a self phase compensation effect of orthogonal boundary layers in a voltage-on state. However, a major drawback of a transmissive LCD is that the backlight source needs to be kept on all the time as long as the LCD is in use. Moreover, an image of the transmissive LCD is easily washed out by a strong ambient light such as direct sunlight. Reflective LCDs, on the other hand, have no built-in backlight source. Instead, reflective LCDs utilize an ambient light for displaying images. In comparison to transmissive LCDs, reflective LCDs have advantages in lower power consumption, lighter weight, and better outdoor readability. However, a reflective LCD relies on ambient light and thus is not suited towards low or dark ambient conditions.
To overcome the drawbacks and take advantages of both of the reflective LCDs and transmissive LCDs, transflective LCDs have been developed. The transflective LCD can display images in both transmissive mode (T-mode) and reflective mode (R-mode) simultaneously or independently. Under bright ambient lights, the backlight of the transflective LCD can be turned off to save power and the transflective LCD operates in the R-mode only. Under dark ambient lights, the backlight is turned on for illumination and the transflective LCD works in the T-mode. In the low-to-medium ambient surroundings, the backlight is still necessary. Since the transflective LCD consists of both T-mode and R-mode, two different phase retardations exist. Thus the transflective LCD has a lower optical performance.
Therefore, what is needed is a method for designing a transflective LCD, in order to control a transmissivity of the transflective LCD and enhance an optical performance of the transflective LCD.